scholarly journals Modelling the Dynamics of Shock Pulse in the Tube with Inner Layer of Aqueous Foam

2021 ◽  
Vol 14 (1) ◽  
pp. 118-125
Author(s):  
R.Kh. Bolotnova ◽  
◽  
E.F. Gainullina ◽  
Keyword(s):  
Shock Pulse ◽  
Aqueous Foam

Influence of aqueous foam syneresis on the shock wave propagation velocity

2020 ◽  
Vol 15 (3-4) ◽  
pp. 159-166
Author(s):  
E.F. Gainullina
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Numerical Solutions ◽  
Liquid Fraction ◽  
Pulse Velocity ◽  
Shock Pulse ◽  
Contact Heat ◽  
Two Phase ◽  
Aqueous Foam ◽  
Droplet Mixture

Numerical simulation of the spherical shock pulse propagation in aqueous foam with volumetric liquid fraction of 0.0083 has been carried out in accordance with the published experimental data on the explosion of HE in aqueous foam. The assumption is used that the foam structure is destroyed by the shock wave, which leads to the transformation of the foam into a monodisperse gas-droplet mixture. The system of equations for the two-phase gas-droplet model of aqueous foam includes the laws of conservation of mass, momentum, energy for each phase and the equation for the dynamics of the volumetric liquid fraction in a single-pressure, two-velocity, two-temperature approximations in a three-dimensional formulation and takes into account the forces of the Schiller-Naumann interfacial drag, the Ranz-Marshall interphase contact heat exchange and the effect of foam syneresis on the initial distribution of its volumetric liquid fraction. Realistic equations of state in the form of Peng-Robinson and Mie-Gruneisen are used to describe the thermodynamic properties of air and water that make up a gas-droplet mixture. Numerical modeling of the processes under consideration was carried out in the open software of computational fluid dynamics OpenFOAM using the finite volume method based on the iterative two-step PIMPLE algorithm. The analysis of the effect of foam syneresis on the dynamics of shock pulse in aqueous foam is given. It was found that the uneven distribution of the liquid fraction in the foam, caused by its sedimentation under the gravity, leads to the increase in the shock pulse velocity in upper layers of the foam. In comparative analysis of numerical solutions and experimental data at sensor locations, the importance of taking into account syneresis phenomena in modeling the dynamics of shock wave in aqueous foam is shown. The reliability of calculations obtained by the proposed model is confirmed by their agreement with experimental data.

Main features of using the shock pulse method for vibration diagnostics of turbogenerator stators

2018 ◽  
Vol 11 (1) ◽  
pp. 36-40
Author(s):  
S. N. Gavrilov ◽  
A. V. Gaev ◽  
V. I. Nikitin ◽  
G. D. Pigrova
Keyword(s):  
Pulse Method ◽  
Shock Pulse ◽  
Vibration Diagnostics

The Numerical Modeling of Spherical Explosion in the Foam

2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Initial Pressure ◽  
Water Volume ◽  
Symmetric Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Initial Water ◽  
Aqueous Foam ◽  
Spherical Explosion

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.

Mitigation of exploding-wire-generated blast-waves by aqueous foam

2015 ◽  
Vol 27 (7) ◽  
pp. 076103 ◽  
Author(s):  
M. Liverts ◽  
O. Ram ◽  
O. Sadot ◽  
N. Apazidis ◽  
G. Ben-Dor
Keyword(s):  
Blast Waves ◽  
Exploding Wire ◽  
Aqueous Foam

Shock-pulse transmission on driving metal tubes into the ground

1998 ◽  
Vol 34 (1) ◽  
pp. 73-79 ◽  
Author(s):  
A. L. Isakov ◽  
V. V. Shmelev
Keyword(s):  
Shock Pulse ◽  
Pulse Transmission
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